The present invention relates to a method and composition for selectivity staining dentin so that the relative positions of dentin and enamel in a tooth preparation can be observed, making possible the independent preparation of enamel and dentin.
As is known to those skilled in the art, composites such as are disclosed in copending Ser. No. 040,636, filed Apr. 21, 1987 (incorporated herein by reference) are increasingly becoming accepted as filling materials, in place of amalgam, in tooth restorations.
A tooth consists of three essential parts, a rather soft center called the pupa which contains the nerves of the tooth, a relatively hard proteinaceous dentin, and a very hard enamel coating. The enamel is relatively non-porous and is resistant to penetration by foreign substances, whereas the dentin is relatively porous because it is living tissue. It is difficult, however, for the practitioner to detect the difference between enamel and dentin using the naked eye.
In the preparation of a composite tooth restoration, it is sometimes desirable to acid etch the tooth enamel in the area adjacent to the cavity or tooth wall requiring restoration so that the composite material can be bonded to the enamel to provide a mechanical retention of the composite. It has been shown in the art that acid etching of the enamel increases the bond strength between composite materials and enamel. Because dentin is living tissue, however, if acid from the acid etching procedure contacts the dentin, the acid may harm the dentin and may cause the patient great pain. Also, placing composite materials over injured dentin tissue may lead to future complications in the tooth.
There are stains known in the art which will stain plaque, which makes it easier for the practitioner to remove plaque. It is known in the art that plaque is bacteria generated protein. It has been discovered in accordance with this invention that known substances used to stain plaque will also stain dentin, providing a line of demarcation between dentin and enamel in a tooth preparation, since enamel is not proteinaceous, and will not be stained by the substances.
Accordingly, it is the object of the invention to make the preparation of composite restoratives easier and safer.